| Key Facts |
| Bridge Name | Facility Carried / Feature Intersected | Location | Structure Type | Construction Date / Builder or Contractor |
| Boulevard of the Allies Bridge | Boulevard of the Allies (PA-885) Over Various Streets | Pittsburgh: Allegheny County, Pennsylvania | Metal Through Girder, Stationary | 1928 By: McClintic-Marshall Company of Pittsburgh, Pennsylvania |
| Technical Facts |
| Structure Length | Roadway Width | Bridge Width | Minimum Vertical Underclearance | Main Spans | Approach Spans |
| 351 Feet (107 Meters) | 40 Feet (12.2 Meters) | 46 Feet (14 Meters) | 16 Feet (4.9 Meters) Over Highway | 2 | 6 Stringer/Girder |
This bridge was significant as an early example of an attempt by Pittsburgh to deal with traffic congestion that began to manifest itself as the city grew and people were driving more often. It was also a very early example of a transportation system that displayed the qualities of an interchange, with a combination of onramps and grade separations. The bridge was also a significant example of plate girder technology, as it was a bridge of decent length that also included inclines and curves in the design. The bridge was fabricated by the McClintic-Marshall Company which was a very important bridge company that was based right in Pittsburgh. The company fabricated some famous landmark bridges including the Ambassador Bridge in Michigan. The Boulevard of the Allies Bridge was a smaller, but local example of this prominent company's work.
Note that there were multiple structures composing this interchange/bridge. The technical facts presented represent the largest main section of the bridge.
Information and Findings From Pennsylvania's Historic Bridge InventoryDiscussion of Bridge The skewed, 8-span, 351' long, built up thru girder bridge is supported on heavy built up bents on concrete plinths. The floor beams are built up, and the stringers that are framed into the floor beams are rolled. The bridge has no innovative or distinctive details, and it is not technologically significant. The railroads had been using similar heavy girder bridges for well over 50 years. It is historically locally significant in association with Pittsburgh's early traffic engineering campaign. The Boulevard of the Allies was the early roadway effort to improve traffic into the city from the east. The boulevard has too many alterations to be a historic district, but isolated structures like this one mark the early effort. Discussion of Surrounding Area The bridge carries 4 lanes of the limited access Boulevard of the Allies over 2 city streets and an exit ramp from I 376 in Pittsburgh's Oakland section. The area of mixed commercial and residential use does not appear to be a potential historic district. The bridge was built as part of the construction of the Boulevard of the Allies, one of the first attempts by the city and county to alleviate downtown Pittsburgh traffic congestion problems. The route itself has too many alterations to be a historic district. Bridge Considered Historic By Survey: Yes |
